17 samples were collected from aeolian and lacustrine profiles within the environment sensitive zone of the Loess Plateau, and an experimental method was established which is suitable for pollen extraction from aeolia...17 samples were collected from aeolian and lacustrine profiles within the environment sensitive zone of the Loess Plateau, and an experimental method was established which is suitable for pollen extraction from aeolian sediment. A comparative study of pollen dating was carried out using the accelerator mass spectrometry (AMS)14C dating of known age samples, and then an experiment with the pollen concentrates was performed. The results indicate that pollen that has been deposited simultaneously with sediment in a stable environment can provide reliable ages. This technique will provide a way of improving the chronological framework for the Loess Plateau since the late Pleistocene. TheI4c dating was combined with field investigations, and from the geological record within this zone, evidence was extracted of four major monsoon precipitation changes during the transition from the late Pleistocene to Holocene.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 49894170, 49725308)Chinese Academy of Sciences (Nos. KZ-951-A1-402 & KZ-952-S1-419)State Committee of Science and Technology of China.
文摘17 samples were collected from aeolian and lacustrine profiles within the environment sensitive zone of the Loess Plateau, and an experimental method was established which is suitable for pollen extraction from aeolian sediment. A comparative study of pollen dating was carried out using the accelerator mass spectrometry (AMS)14C dating of known age samples, and then an experiment with the pollen concentrates was performed. The results indicate that pollen that has been deposited simultaneously with sediment in a stable environment can provide reliable ages. This technique will provide a way of improving the chronological framework for the Loess Plateau since the late Pleistocene. TheI4c dating was combined with field investigations, and from the geological record within this zone, evidence was extracted of four major monsoon precipitation changes during the transition from the late Pleistocene to Holocene.
